The present invention relates to a storage system and scheduling method that adjusts the balance between processing time for task processing, and interrupt processing requested internally or externally.
In a database system such as a data center, that manages a large volume of data, data is managed by using a storage system such as a disk array system. A disk array system has a number of storage devices arranged in arrays, and provides storage resources in RAID (Redundant Arrays of Independent Inexpensive Disks) form to a host computer. The host computer and storage system are mutually connected via a device-sharing network such as a SAN (Storage Area Network).
The network-connected storage system executes not only processing requested internally, including recovery processing for recovering any failure occurring in the disk drives, self-diagnosis processing for checking whether or not a failure is present in any disk drives, and backup processing for backing up data, but also processing requested externally, including access from a host computer and various network servers.
Of the processing requested internally and externally, processing that needs a real-time response (readiness) has to be performed promptly, and efficient scheduling is necessary. For example, Japanese Patent No. 2918297 proposes an interruption control method for temporarily stopping non-interrupt-level processing and executing interrupt-level processing when that interrupt-level processing is requested.